Review nested message kind groups with exact timer scope

harness/release-semantic-gui.md

@@ -1,7 +1,8 @@
-# Semantic desktop review — milestones 1 and 2
+# Semantic desktop review — scalars and nested message kind
 
-Status: milestones 1–2 implemented and desktop tests/build verified; not full GUI
-parity, native acceptance or release acceptance.
+Status: milestones 1–2 implemented; the bounded MessageKind/TimerExpression
+constructor slice is implemented. Full milestone 3, GUI parity, native acceptance
+and release acceptance remain outstanding.
 Base: `d130013`. Dedicated build target:
 `D:/CodexBuilds/Capella2-semantic-desktop-target`. Native verification is root-owned.
 
@@ -16,7 +17,8 @@ Base: `d130013`. Dedicated build target:
 - Support every applicable scalar leaf through Keep, Take and typed final-value
   forms. Candidate records contain the complete combined selected result. Identity,
   alias and layer are protected. The closed core remains the validation boundary.
-- State.Kind is a single structural scalar. Other constructor switches, keyed
+- State.Kind is a single structural scalar. Occurrence.MessageKind now supports
+  its complete nested group, including TimerExpression. Other constructor switches, keyed
   membership/order/annotation/binding/attachment decisions and pairing resets belong
   to milestone 3; show them read-only with an honest explanation.
 - Core `6bb2583` permits first equal constructor acknowledgment without descendant
@@ -36,14 +38,16 @@ Base: `d130013`. Dedicated build target:
 2. Scalar decisions and typed candidates; immutable initial observations; combined
    final records; exact impact acceptance; atomic document/source commit. Focused
    App event/source/history tests, strict Clippy and a dedicated desktop build.
-3. Constructor closure, keyed and ordered facts, reset, complete artifact lifecycle,
-   multi-source review and remaining source/REST parity cases. Still outstanding.
+3. Nested MessageKind/TimerExpression closure is implemented. Other constructor
+   groups, keyed and ordered facts, reset, complete artifact lifecycle, multi-source
+   review and remaining source/REST parity cases are outstanding.
 4. Root-owned native review, cross-surface fixtures, package/release acceptance.
 
 ## Verification
 
-Verified after the independent scalar review fixes on SEM `6ad3cb`, using only the
-dedicated desktop target (core behavior remains based on `6bb2583`):
+Scalar fixes were verified on SEM `6ad3cb`; the nested message-kind slice builds
+on scalar commit `5a51a75`. Verification uses only the dedicated desktop target
+(core behavior remains based on `6bb2583`):
 
 ```powershell
 $env:CARGO_TARGET_DIR='D:/CodexBuilds/Capella2-semantic-desktop-target'
@@ -52,8 +56,8 @@ cargo clippy --locked -p oa-desktop --all-targets -- -D warnings
 cargo build --locked -p oa-desktop
 ```
 
-All **277 desktop tests passed**, including **11 original semantic review tests**
-and **5 scalar review regression tests**.
+All **285 desktop tests passed**, including **11 original semantic review tests**,
+**5 scalar review regression tests**, and **8 nested message-kind tests**.
 Strict Clippy and the desktop build passed. The existing migration test's header
 assertion now follows `SCHEMA_VERSION` instead of expecting schema 4.
 
@@ -85,19 +89,56 @@ The independent scalar review found three gaps, now corrected:
 The regression tests exercise App events, the actual default-form helpers and
 button availability, exact source retention before Apply, and one-step undo.
 
+## Bounded constructor slice
+
+Occurrence.MessageKind is a complete closed nested family: Asynchronous, Call,
+Reply, Create, Delete and Timer. It is available only when both traced counterparts
+are Exchange occurrences. The only constructor-specific payload is the timer
+expression. Outer occurrence replacement remains read-only.
+
+- Keep/Take/Candidate use the core's switch and first-equal acknowledgment policy.
+  Taking a replacing group copies the typed MessageKind, including its expression.
+  Taking an initial equal discriminator does not copy an unselected timer value.
+- Candidate MessageKind has its own scoped draft. The independent TimerExpression
+  scalar draft survives group decisions; the group timer's exact raw text, editor
+  cursor and selection survive switching away from Timer and back.
+- An overlapping kind/timer draft retains both decisions and blocks Apply until
+  explicitly resolved. The dialog offers **Replace timer decision with message-kind
+  group** and **Leave message kind unselected; use timer decision**. First equal-kind
+  acknowledgment can coexist with an independent timer decision. Divergent authored
+  candidate values reject; neither candidate silently overwrites the other.
+- The kind detail includes baseline/current timer observations and the complete
+  proposed kind. It displays the exact plan-provided acknowledged/retired lists.
+  Exchange, reply-to, lifelines, annotations and pre/postconditions stay separately
+  scoped. Incompatible Timer contracts remain core errors; no dependency or payload
+  is silently removed. Existing additional-impact approval remains in force.
+- Group changes compose with scalar choices and execute the exact prepared Document
+  batch. Tests cover both directions, all six kinds, mapped reply correlation,
+  historical retirement, repeated no-switch rejection, invalid combinations,
+  protected scopes, stale preview, source failure, comments and one-step undo/redo.
+- The Traceability contextual toolbar now wraps at the available width so +Artifact
+  remains reachable in the compact layout. This is a single `row.wrap()` change in
+  `views.rs`; other toolbars are outside this slice.
+
+Root reported native scalar coverage on frozen integrated `e7fa061`: mixed numeric
+Keep/Take/Candidate, invalid default retention/repair, zero additional changes,
+atomic Apply, comment/value inspection, Undo/Redo and Save All at 1440×900 and
+1100×700. Reverse/type/reference/history/reopen native checks were still continuing
+when this slice was implemented. This task launched no native application.
+
 Built executable:
 `D:/CodexBuilds/Capella2-semantic-desktop-target/debug/arcadia-studio.exe`.
 The build target is idle. No native application was launched by this task.
 
 ## Remaining work
 
-Milestone 3 must add explicit constructor closure/replacement, keyed and ordered
+Milestone 3 must add the remaining constructor closure/replacement, keyed and ordered
 decisions, historical pairing reset, complete artifact lifecycle and multi-source
 review. These facts are currently inspectable, with unsupported writes visibly
 identified. The reference table supplies explicit mappings for scalar reference
 Take; it does not claim to complete a reset or establish keyed acknowledgments.
 
-Fresh independent scalar GUI review and root-owned native verification are still
-required before merging this milestone into release acceptance. In particular,
-validate the 1100×700 layout, keyboard/focus continuity, long historical values,
-reference selection, source reopening and prepared-impact inspection in the app.
+Fresh independent requirements/correctness review and root-owned native checks of
+the message-kind slice are required before release acceptance. Verify the compact
+kind picker, timer text/focus retention, overlap choices, exact closure/retirement,
+mapped Reply, blocked Timer contract, source reopening and toolbar wrapping.